Plasma cell neoplasms (PCN), including multiple myeloma, are tumors of terminally differentiated B cells. Despite a significant research effort, and numerous advances in therapy, most tumors of this B cell lineage remain incurable. To this end, understanding factors which are critical for the development of PCN may lead to new avenues for therapy. Interleukin-6 (IL-6) is a pleiotropic, pro-inflammatory cytokine which supports the growth, proliferation, and survival of myeloma cells. We found that inflammation, and in particular, IL-6 is critical for the development of PCN. In order to determine if tumor microenvironment (TME) or B cell-derived IL-6 was more important in PCN development, we utilized an adoptive transfer system of tumor formation. By adoptively transferring premalignant B cells into recipients, and then providing the B cells with an inflammatory microenvironment through the use of pristane, we were able to generate donor tumors in recipient mice. Utilizing this method, a series of adoptive transfers were performed to determine the primary source of IL-6 in murine PCN development. We discovered that TME-derived IL-6, and not B cell-derived IL-6, is most critical for PCN development. Furthermore, in studying the lesions in B cell development which lead to tumor formation, we discovered that IL-6 collaborates with the proto-oncogene c-Myc in spontaneous germinal center (GC) formation. The spontaneous GCs were accompanied by a robust follicular T helper cell response. In characterizing the genetic lesions which lead to the GC formation, we discovered that Myc-transgenic mice develop a significant increase in the population of B1a B cells. Furthermore, these B1a B cells infiltrate the spontaneous GCs of double transgenic Myc/IL-6 mice. Lastly, utilizing our adoptive transfer method, we determined that the germinal center response is necessary for the development of PCN in mice. Lastly, we focused our efforts on another oncogene which collaborates with IL-6, BCL-2. Double transgenic BCL-2/IL-6 mice develop PCN and spontaneous GCs. Of interest however, the adoptive transfer of BCL-2/IL-6 B cells results in tumor formation without the use of pristane. Furthermore, the adoptive transfer recipients develop bone lesions, hind limb paralysis, and a monoclonal gammopathy. This model closely recapitulates many of the pathophysiological features seen in human PCN. This new model promises to be important for future studies into PCN development and treatment.

No description available.

viii, 122 leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (M.D.)--University of Adelaide, Dept. of Medicine, 1974

No description available.

Thesis (Ph.D.)--University of Delaware, 2006. / Principal faculty advisor: John K. Rosenberger, Dept. of Animal and Food Sciences. Includes bibliographical references.

Epstein-Barr virus (EBV) has infected 95% of the adult population. Yet, EBV stays as a harmless passenger in infected B-cells of nearly every host. EBV depends on a careful balance between the immune system and the virus that becomes evident when the host is immunocompromised. In such individuals, EBV can manifest as one of many associated malignancies. In children who have undergone solid organ transplantation, EBV-driven post-transplant lymphoproliferative disease (PTLD) can cause significant morbidity and mortality. We examined EBV-infected cells in non-diseased pediatric transplant recipients with elevated viral loads in their peripheral blood. Examination of high EBV genome copy cells in high load patients with a combined fluorescent in situ hybridization and immunofluorescence procedure demonstrated that the majority of high copy cells had no discernible expression of immunoglobulin on the surface (Ig-null cells). Such cells are lacking the crucial survival signal provided by an intact BCR and should not survive in the circulation. By flow cytometry, high load patients were shown to have the highest percentage of Ig-null cells in their peripheral blood; those with low viral loads and non-detectable viral loads had lower percentages. The phenotype of Ig-null cells was shown to differ from the resting memory B2 phenotype of normal latently infected B cells, with variable expression of CD20, CD40, and HLA Class I and II. Sorting Ig-null cells from the peripheral blood of high load carriers further demonstrated that in all patients examined, a large portion of the viral load was carried in the Ig-null compartment. Virus was also detected in the Ig-null, CD20- and HLA Class I- compartment, with a variable enrichment of the viral load in these compartments from patient to patient. Ig-null cells have been reported in the tumors of other EBV-associated malignancies, including PTLD, but never in the peripheral blood or in a non-disease state. This study has public health relevance because PTLD carries significant morbidity and mortality to transplant recipients; the presence in the blood of aberrant Ig-null cells which should have followed a program of apoptosis might be a risk factor for the development of PTLD or another EBV-associated disease.

Human herpes virus8 (HHV-8) is a known carcinogenic agent. This report investigates five populations to determine if HHV-8 was associated with disease onset. Detection and levels of antibodies were measured using an enhanced immunofluorescent assay and were analyzed with the statistical program, SPSS. In the first study, we tested the hypothesis that HHV-8 was the causative agent in Langerhans cell histiocytosis (LCH). The seroprevalence of HHV-8 among 159 LCH patients was similar to the control group, indicating that HHV-8 is not the etiological agent of LCH. In the second study, we tested the hypothesis that HHV-8 reactivation occurs in solid-organ transplant (SOT) patients, following immunosuppression. We found a significant increase in HHV-8 seropositivity when comparing pre-transplant to post-transplant samples (p-less than .01). There was also an overall increase in viral antibody titers following transplantation (p=less than .001), indicating viral reactivation. In the third study, we compare the SOT results to bone-marrow transplant patients (BMT). Longitudinal serum samples from 34 BMT patients did not demonstrate a significant association with HHV-8 as compared to the control (p=.716) or the SOT populations (p=.180). In addition, HHV-8 reactivation did not occur post-transplantation. In the fourth study, we tested the hypothesis that HHV-8 is associated with increased risk of prostate cancer (PrCa). There was greater than a 2-fold association between HHV-8 seroprevalence and PrCa among African-Caribbean men from Tobago (p=.003). A similar trend was present in a PrCa cohort from the United States, p=greater than .05. In a fifth study, we tested the hypothesis that HHV-8 increased the risk of PrCa among men who carried genetic polymorphisms in the androgen (AR) and estrogen receptor (ESR1) genes. This study analyzed an expanded Tobago cohort, which demonstrated an association between HHV-8 and PrCa (OR 1.74, p=.032). An increased association was found among seropositive men carrying the high-risk AR allele (OR=2.46, p=.023) and ESR1 allele (OR=3.10, p=.004). The strongest association was found in seropositive men with both high-risk alleles (OR=5.20, p=.017). This study demonstrates the use of HHV-8 serology as a marker for an increased public health cancer detectable risk, due to viral prevalence or reactivation.

Virus-specific memory CD8+ T cells play a prominent role in protection of a host from recurring and persistent virus infection. It is known that memory CD8+ T cells undergo a series of differentiation stages to become fully matured effector cells. There are several important aspects of the current CD8+T cell memory phenotype model that need to be more thoroughly defined. In specific aim 1, it was hypothesized that CD27+CD28+ undifferentiated CD8+ memory T cells specific for non-persistent virus influenza A (FluA) would have phenotypic markers associated with more differentiated (effector) phenotypes. Results showed that in spite of the phenotypic enrichment of FluA-specific memory CD8+ T cells in the undifferentiated stage, they displayed effector markers indicative of late stage differentiated effector cells. In specific aim 2, it was further hypothesized that the most undifferentiated CD62L+ central memory CD8+T cells would have the effector function including immediate cytoplasmic production of gamma-IFN upon antigenic-stimulation. Results showed that CD62L+ CD8+ T cells are capable of immediate gamma IFN production after antigen-specific stimulation in the presence of the CD62 sheddase inhibitor, GM6001, highlighting the need to re-evaluate the defining markers of virus-specific central memory CD8+ cells and/or their functions. In specific aim 3, this dissertation tests the hypothesis that memory-effector differentiation of HIV-1-specific memory CD8+ T cells is impaired during the course of persistent HIV-1 infection. Detailed comparison of CD27 and CD57 co-expression on HIV-1-specific CD8+ T cells showed that these cells had a significantly lower proportion of the CD27CD57high effector subset. Moreover, these cells did not display progression from CD27+CD57 (immature memory), through CD27lowCD57low (transitional memory-effector) to CD27CD57high (effector subset) that was seen in well differentiated EBV-specific CD8+ T cells and was common in CMV-specific CD8+ T cells. These observations suggest that the normal course of HIV-1-specific CD8+ T cell memory-effector differentiation is impaired during the course of persistent HIV-1 infection. Elucidation of memory-effector differentiation of virus-specific CD8+ T cells has significant public health implications. Understanding the impairment of memory-effector differentiation of HIV-1-specific CD8+ T cells, for instance, will greatly facilitate a design of effective vaccine against progressive HIV-1 infection.

Approximately 25-30% of people infected with human immunodeficiency virus 1 (HIV-1) develop HIV-associated encephalitis and HIV-associated dementia. The underlying mechanisms leading to HIV encephalitis remain unclear. In an attempt to understand the molecular events that lead to encephalitis and subsequent dementia, I focused on identifying differentially expressed genes in the central nervous system (CNS) using SIV infected rhesus macaques as an experimental model system by using methods serial analysis of gene expression (SAGE), and microarray hybridization. I studied two different brain regions, caudate and globus pallidus, in non-infected, acutely infected, and mildly encephalitic animals. Since my analysis of macaque SAGE data utilized existing human nucleotide sequence databases, identification of the genes from which the SAGE tags were obtained proved to be challenging. I successfully identified the genes from which two of the tags were obtained. These were major histocompatibility complex class I (MHCI), differentially expressed during disease and neurogranin (Nrg), differentially expressed in caudate relative to globus pallidus. The differential expression of these two genes was confirmed by real-time RT-PCR and in situ hybridization techniques. I further characterized the localization of MHCI in the CNS tissue and found that whereas in non-infected tissues, endothelial cells were the major cell types expressing MHCI mRNA, during acute infection and mild encephalitis, when local virus replication was low or absent, all CNS cell types could express this mRNA. In addition, I observed upregulation of interferon-stimulated genes (ISGs), MxA, OAS2, and G1P3, both in the CNS and in the periphery that could be potential surrogate markers for SIV infection. Since encephalitis is observed only at end-stage disease, traditional thinking has been that the CNS remains relatively unaffected until later stages of infection. Our findings indicate that immune activation within the CNS might occur early in infection and persist in a chronic manner thereby causing continuous damage, which might affect the development of end-stage encephalitis and dementia. Therefore, early, potent, suppression of systemic viral replication could potentially inhibit the development of virus-mediated neuropathology later on. Such an approach would be of important public heath significance.

Human metapneumovirus (hMPV) is a recently discovered paramyxovirus known to cause respiratory tract infections primarily in children. This previously unknown pathogen remained undetected for years due to very slow replication in vitro and an inconsistent CPE. More recently, detection of hMPV by means of quantitative molecular techniques has proved to be more effective than culture methods. In this study we describe the development of a quantitative real time RT-PCR assay targeting the hMPV nucleoprotein (N) gene. This assay is compared to a real time nucleic acid sequence based amplification (NASBA) test, developed by bioMérieux, using control material from hMPV strains Can97-83 and Can98-75 representative of the two main lineages A and B, respectively. Using control material the real time RT-PCR, designed to detect all four sublineages of hMPV, can detect as low as 50 and 100 copies of viral RNA from the A and B lineages respectively. The real time NASBA assay can also detect 50 copies of viral RNA from the A strain but only detects 1000 copies of strain B viral RNA. In this study, hMPV has been detected in both immunosuppressed lung transplant recipients (2.14%) and children with respiratory symptoms (1.83%). This research is of major public health significance due to the amount of respiratory infections that are going undiagnosed or being treated with unnecessary antibiotics. It is important for our physicians to not only know that hMPV is present in our community but also to be able to detect and treat it appropriately. This study reports the first evidence of hMPV in the Pittsburgh area and demonstrates the importance of this virus as a critical player among respiratory pathogens in both immunosuppressed lung transplant recipients and children. In conclusion, we have successfully developed a real time RT-PCR assay targeting the hMPV N gene. Using this assay along with the real time NASBA assay developed by bioMérieux, we have detected hMPV infections in lung transplant recipients in a year long study. Using the real time RT-PCR assay alone hMPV has also been detected in children suspected of respiratory infection during the early winter season.